Widely known at present is a method of measuring the direction o f mechanical vibrations residing in that secured to a vibrating object is a spring-loaded needle which when vibrating traces a trajectory of the object vibrations on a coated glass fixedly installed along the base line which is a reference line for taking readings of angles. An angle between a straight line passing through the extreme, most distant, points of the trajectory and the base line characterizes the direction of vibrations and is measured with a protractor.
Said method is characterized by a low accuracy due to an error introduced at setting of the protractor relative to the base line, a small measurement base between the extreme points of the trajectory and an error in defining of the extreme points in case of elliptic vibrations. A total error amounts to .+-.6.degree.. Another disadvantage of the method resides in a tedious measuring procedure due to complexity in securing the needle on an object and the glass on a stand.
Because of the above-mentioned disadvantages the use of said method fails to provide the rapid accomplishment of periodical checks on the direction of mechanical vibrations being one of the main parameters of vibration machines and to adjust the vibration machine with an ample accuracy for an optimum mode of operation with regard to this parameter.